Tag Archives: untouched

The Unique Galaxy Reveals Surprisingly Untouched Stars.

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Abell 2744, Amore6 Discovered Galaxy Cluster

NASA, ESA, Jennifer Lotz, Matt Mountain, Anton M. Koekemoer, HFF Team (STScI)

In the vast expanse of the universe, galaxies that exhibit peculiar contours are surprisingly filled with ancient stars. This offers astronomers an initial peek into a unique type of stellar body that emerged soon after the universe’s inception.

Although the James Webb Space Telescope (JWST) has allowed scientists to revisit regions of the early universe, pinpointing the first stars remains elusive. These primordial stars, termed Population III stars, are primarily colossal hydrogen spheres believed to have formed in the universe’s infancy. As the very first stars, they left behind an environment largely devoid of heavier elements following their demise.

While there have been theories hinting at the existence of such stars, definitively proving their existence in the early universe has been challenging, as galaxies appeared to have become tainted with heavier elements merely a few hundred million years post-Big Bang.

Recently, Morihara Highlands from the California Institute of Technology and his team found a galaxy almost entirely composed of hydrogen, indicating the presence of Population III stars. However, this galaxy emerged later than expected, approximately a billion years after the universe began.

Dubbed Amore6, it was initially identified within the Abell 2744 galaxy cluster. Upon measuring the light from Amore6 using the JWST, Morishita and his colleagues noted the complete absence of common oxygen ions. This suggests that the galaxy harbors less than 0.2% of the oxygen present in our sun, indicating a lack of contamination by heavier elements.

As the universe evolves, the likelihood of encountering such pristine galaxies diminishes. In images captured by the JWST, Amore6 appears somewhat isolated, which Morishita posits could be a factor in its untouched state. “This seclusion might mean that this galaxy has not yet encountered sufficient gas to trigger star formation, implying that it could evolve slowly,” he mentions.

“If these findings are validated, it would be truly astonishing, as we did not anticipate discovering such an untarnished galactic environment later in the universe’s development,” says Fabio Pacucci of the Harvard Smithsonian Astrophysics Center in Massachusetts.

This discovery has implications for observing “direct collapse” black holes. Unlike the conventional pathway of collapsed stars, these black holes form from massive clouds of untainted gas. While astronomers had predicted their existence, they have never actually formed as it was believed that primitive gas was only available for a limited period, up to 100 million years after the Big Bang. However, if this untainted gas can persist for an extended duration, the potential for observing such phenomena increases, Pacucci argues.

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Source: www.newscientist.com

New studies indicate Arrokoth and other Kuiper belt objects are made of untouched ice

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A pair of planetary scientists from Brown University and the SETI Institute have uncovered ancient ice deep within Arrokoth, the Kuiper Belt object (486958) that was the focus of a flyby by NASA’s New Horizons mission on January 1, 2019. They suggest that billions of years ago when the object first formed, there was a chance that ancient ice formed by comets could be present. By developing a new model to study comet evolution, the researchers found that this endurance is not unique to Arrokoth but may also be found in many other objects in the Kuiper belt.

This composite image of Ultima Thule was compiled from data acquired when NASA’s New Horizons spacecraft flew by the object on January 1, 2019. This image combines enhanced color data (close to what the human eye can see) with detailed high-resolution panchromatic data. picture. Image credit: NASA / Johns Hopkins University Applied Physics Laboratory / Southwest Research Institute / Roman Tkachenko.

“Using a fairly simple mathematical model, we now show that primordial ice can be trapped deep inside these objects for long periods of time,” said Dr. Sam Birch, a planetary scientist at Brown University. “Most of our community thought this ice should have disappeared long ago, but now we think that may not be the case.”

Planetary scientists have long struggled to understand what happens to the ice on these space rocks over time. The new study challenges traditional thermal evolution models and suggests that highly volatile ice on these objects may persist longer than previously thought.

A model created by Birch and SETI Institute researcher Orkan Umurkhan explains this phenomenon, indicating that the ice on these objects can endure due to their extremely low temperatures. This new idea may provide insight into the explosive nature of icy objects in the Kuiper belt when they approach the sun.

Ultimately, this study presents a new perspective on comet evolution and activity, challenging existing theories and paving the way for a deeper understanding of these celestial bodies and their origins.

Birch and Dr. Umruhan are co-investigators of NASA’s Comet Astrobiology Exploration Sample Return (CAESAR) mission, which aims to collect surface material from comet 67P/Churyumov-Gerasimenko and return it to Earth for analysis, potentially shedding further light on comet evolution and activity.

The study is published in the journal Icarus, and the results could have implications for future space exploration missions and our understanding of the cosmos.

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Samuel PD Birch and Orkan M. Umruhan. 2024. 486958 CO ice and gas remain inside the Arokos. Icarus 413: 116027; doi: 10.1016/j.icarus.2024.116027

Source: www.sci.news

The surface of Enceladus may have significant amounts of untouched organic material

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Enceladus, Saturn’s sixth-largest moon, is an interesting place to look to our solar system in the search for evidence of extraterrestrial life, given its habitable oceans and plumes that deposit organic-containing marine material on its surface. It brings you the right opportunities. Organic marine material may be sampled by the Enceladus lander mission. Considering the UV and plasma environment, it is interesting to understand the amount of relatively pure and unaltered organic matter present on the surface.

Enceladus’ tiger stripes are known to be caused by the moon’s icy interior spewing ice into space, creating a cloud of fine ice particles above the moon’s south pole, forming Saturn’s mysterious E ring. It is being This evidence comes from his NASA Cassini spacecraft, which orbited Saturn from 2004 to 2017. Shown here is a high-resolution image of Enceladus taken from a nearby airfield. The tiger stripes appear in a false blue color. Image credit: NASA / ESA / JPL / SSI / Cassini Imaging Team.

“By sending a mission to the surface of Enceladus, we can learn a lot about the biological signatures that may exist in Enceladus’ oceans,” said Amanda Hendricks, a senior scientist at the Planetary Science Institute. .

“Previously, it was thought that sampling the freshest material from Enceladus’ ocean would require flying through the plume and measuring plume particles and gas.”

“But now we know that we can land on the surface, and we are confident that the instrument can measure plume organic matter from the ocean in its relatively natural state.”

“Thanks to measurements from NASA’s Cassini spacecraft, we know that Enceladus’ ocean is habitable,” she added.

“We know that there is liquid water, energy, and chemicals such as carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur, which are necessary for life as we know it. It is an ingredient.”

“Enceladus is an oceanic world. Beneath its icy surface is a liquid ocean.”

“There are at least some ocean worlds in our solar system, but Enceladus is special because it is spraying ocean material into space via plumes of water vapor and ice particles at its south pole. This means Cassini’s instruments were able to reveal its signature.” As the spacecraft flew through Enceladus’ plumes, the ocean was visible. ”

“Fortunately, this study found that even though some of the plume particles were ejected into the Saturn system, nearly 90% of the plume particles returned to the Moon’s surface. This is likely due to marine material containing organic matter. But it’s sitting right on the surface.”

Organic molecules found in Enceladus’ plumes include molecules such as methane and ethane, as well as more complex molecules.

Organic matter is processed or chemically transformed by charged particles such as the sun’s ultraviolet photons and electrons.

But if scientists want to know whether ocean-derived biosignatures are present in plume particles, they need these particles to be as pristine as possible and unexposed to ultraviolet light.

An artist’s impression of NASA’s Cassini spacecraft flying through a plume of smoke spewing from Enceladus’ south pole. These plumes are much like geysers, releasing a combination of water vapor, ice grains, salt, methane, and other organic molecules. Image credit: NASA/JPL-Caltech.

In the new study, Dr. Hendricks and fellow Penn State researcher Christopher House use data from NASA/ESA’s Hubble Space Telescope and Cassini to show that ultraviolet photons can be detected on Enceladus’ plume-covered surface. We estimated how deep it could penetrate.

“What we found in this study is that there are places on the surface of Enceladus where a spacecraft can land and collect samples. If we do that, we could measure organic matter in a relatively natural state.” Dr. Hendricks said.

“That’s because the sun’s ultraviolet photons don’t penetrate very deeply into the ice surface.”

“These harmful solar UV photons only penetrate about 100 micrometers into the ice surface. That’s the width of several human hairs!”

“So the topmost surface is exposed to harmful UV photons, but only some of the organic matter is chemically changed, and soon that material is covered by fresher plume material. .”

“And the deeper particles do not undergo further deformation because the ultraviolet photons are prevented from interacting with the deeper material.”

“The newly deposited plume particles act as a shield for the material below. They act like a sunscreen!”

“Ideally, we would like to someday land on the surface of Enceladus and sample organic matter from the relatively pristine ocean.”

“This result is important because the penetration depth of these harmful ultraviolet photons is so shallow that it suggests that there is a lot of relatively primitive organic matter that can be sampled.”

“Slightly deeper particles are less exposed to UV light, meaning the organic matter has a lower age of exposure.”

“Ultraviolet light easily alters organic molecules, so the depth at which such light reaches the surface of the icy world is critical,” Dr House added.

“Because the penetration depth of ultraviolet light was found to be short, our findings confirm that there is sufficient organic material trapped and preserved within Enceladus’ ice that can be traced back to its oceans. Did.”

“It’s awe-inspiring to think that we can easily obtain so much organic matter from habitable extraterrestrial oceans using known techniques.”

of findings It was published in the magazine Communication Earth and Environment.

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AR Hendrix & CH House. 2023. The effective UV exposure age of organic matter on Enceladus’s surface is low. common global environment 4,485; doi: 10.1038/s43247-023-01130-8

Source: www.sci.news